An experimental testing apparatus for study of suffusion of granular soils in geological structures

This study mainly focuses on the suffusion process of granular soils, especially that filled in geological structures, such as faults and karst conduits. As current devices only can be used for suffusion tests on cylindrical soil specimens, an experimental testing apparatus has been designed and developed for systematic research on the suffusion of granular soils filled in fractures and fractures subjected to unidirectional seepage flow. The permeameter cell is designed to enable free rotation so that unidirectional seepage can be imposed at any angle from 0° to 90°. Experiments on granular soils were carried out under different axial stresses to verify the operability and repeatability of the designed apparatus. The water pressure and axial stress applied on soil specimens were controlled during testing, and the variations of flow rate and hydraulic conductivity with water pressure under different axial stresses were analyzed to study the effect of axial stress on the suffusion of granular soils.